OBJECT: To understand the relationship between the parent artery and its distal arteries, blood vessels running through the subarachnoid space need to be extensively dissected, which is time-consuming. We examined the efficacy of temporary clipping with the indocyanine green (ICG) technique (target-controlled infusion (TCI) technique), in which the parent artery is occluded using a temporary clip, and ICGV (videoangiography) is performed to clarify the relationship between the distal M4 and proximal M2. METHODS: Thirteen radial artery grafts (RAGs) for internal carotid aneurysm underwent TCI to confirm the relationship between M2 and cortical M4. To monitor the perfusion pressure of the cortical middle cerebral artery, superficial temporal artery (STA) to M4 anastomosis was performed before RA-M2 anastomosis. We performed anastomosis of the recipient of STA- M4 that was distal and downstream of the M2 segment that is the recipient of RA-M2 anastomosis. To select the proper recipient M4 of the STA-M4 anastomosis, the ICGV image range was set sufficiently wide to accommodate the possibility that the distal artery was not the one anticipated. ICGV followed complete occlusion by temporary clipping of the recipient M2. RESULTS: In 2 of the 13 cases, the relationship between the M2 and M4 could not be clarified. CONCLUSIONS: In cases with developed collateral circulation or small perfusion area of the occluded M2, it was difficult to ascertain the relationship by TCI. Nevertheless, TCI was useful in 11 of the 13 cases, suggesting that unnecessary dissection in the subarachnoid space may be reduced using this technique.
OBJECT: To understand the relationship between the parent artery and its distal arteries, blood vessels running through the subarachnoid space need to be extensively dissected, which is time-consuming. We examined the efficacy of temporary clipping with the indocyanine green (ICG) technique (target-controlled infusion (TCI) technique), in which the parent artery is occluded using a temporary clip, and ICGV (videoangiography) is performed to clarify the relationship between the distal M4 and proximal M2. METHODS: Thirteen radial artery grafts (RAGs) for internal carotid aneurysm underwent TCI to confirm the relationship between M2 and cortical M4. To monitor the perfusion pressure of the cortical middle cerebral artery, superficial temporal artery (STA) to M4 anastomosis was performed before RA-M2 anastomosis. We performed anastomosis of the recipient of STA- M4 that was distal and downstream of the M2 segment that is the recipient of RA-M2 anastomosis. To select the proper recipient M4 of the STA-M4 anastomosis, the ICGV image range was set sufficiently wide to accommodate the possibility that the distal artery was not the one anticipated. ICGV followed complete occlusion by temporary clipping of the recipient M2. RESULTS: In 2 of the 13 cases, the relationship between the M2 and M4 could not be clarified. CONCLUSIONS: In cases with developed collateral circulation or small perfusion area of the occluded M2, it was difficult to ascertain the relationship by TCI. Nevertheless, TCI was useful in 11 of the 13 cases, suggesting that unnecessary dissection in the subarachnoid space may be reduced using this technique.